Random crashes after PSU failure

[randomnine]

Hey all! I built this PC around three years ago and it's been rock solid until last weekend, regularly staying up for a month or three at a time. On Saturday the PSU blew, taking out the fuse and the circuit breaker. Since then it's been crashing every hour or so as well as exhibiting some other video issues. Can anyone guess what the issue might be? I'm totally stumped, I need this thing for work and I can't afford to replace bits until it works

SYSTEM

PSU: OCZ ZS Series 650W
Motherboard: Asus M4A87TD EVO
CPU: AMD Phenom II X4 955 Black
RAM: TeamGroup Elite Black 16GB (2x8GB) DDR3 PC3-12800C11 1600MHz Dual Channel Kit
GPU: OcUK Value GeForce GTX 460 768MB GDDR5 PCI-Express
HDD1: Crucial RealSSD C300 64GB 2.5" SATA 6Gb/s
OS: Windows 7 Home Premium - Retail (64 bit)

SYMPTOMS

For the past three years it's been running fine on the original power supply, an OCZ ModXStream Pro 600w.

On Saturday the PC powered down suddenly while idle (screen off), blowing the plug's 5A fuse and the house trip switch. Replacing the fuse and disconnecting nonessential parts resulted in more blown fuses. The PSU alone was blowing fuses.

Eventually found a cheap nasty replacement "800W" PSU on Sunday. System powered up but exhibited the following two issues:

1. Instability. It may stay up for 5 minutes or for 2 hours but it crashes, often. It happily crashes in relatively low load situations, when idle, when browsing webpages, etc. Opening lots of webpages quickly seems to be the only thing that will trigger a crash fast.

2. On some boots, the screen - except for the mouse cursor - dims. Like this. The mouse cursor can be visibly twice as bright as "white" areas elsewhere on the screen. This effect persists until the next startup.

On Tuesday I replaced the cheap PSU with the OCZ 650W PSU listed above in Components. This had no effect. Symptoms are the same with either PSU.

STEPS TAKEN

I have:
- disabled all overclocks
- checked the fans and temperatures
- reset CMOS
- reflashed the BIOS
- installed the latest chipset driver
- deleted and updated the graphics card driver
- tried unplugging everything except the listed components, mouse, keyboard and monitor
- tried underclocking the GPU
- checked the Windows event log: Windows isn't recording the crashes
- run Memtest86: no errors found
- tried loading the system with Prime95 and FurMark for maybe 15 minutes at a time: neither causes crashes or shows up any problems
- tried running various games, but there's no obvious corruption or anything and nothing seems to cause crashes reliably
- tried running it in Safe Mode with Networking. Neither issue comes up in Safe Mode but they both come back on a full boot.

Any ideas for what might be wrong or for further tests to try? Nothing that runs in a full boot and takes more than half an hour 'cause it'll probably crash before it finishes

Thanks!

 

[dt97583]

Corrupt HDD / SSD? Can you run a live Linux CD and leave it to see if it crashes? If not run some manufacturer tools to check the integrity of the disk / SSD?

Maybe remove GPU and run off inbuilt graphics (is this available for AMD mobos?)

Reinstall OS?

 

[Leprechaun312]

would not have gone and bought another OCZ psu, they aren't the best, however it does sound like possibly a corrupt hdd/ssd or your possibly looking at damaged components possibly the graphics card. do you have another one you could test?

 

[biuro74]

Mate, if PSU blew up first thing to worry about is motherboard (see capacitors and a fried areas like PSU main socket, if any, but it's all you can do yourself).
Try to borrow similar mobo and put rest of your components and try to test this way.

 

[randomnine]

Wicked, thanks. Hadn't occurred to me the SSD might be doing it but yeah, web browsing seems to be what kills it and that does lots of little writes...

The PC crashed from Safe Mode this morning so Safe Mode doesn't fix it, just makes it a bit more stable.

I can't see anything obviously blown on the motherboard.

My motherboard doesn't have onboard graphics but I've found an old Radeon X800 GTO kicking around that I'd forgotten about. I've plugged that in instead of the GTX 460 and the PC's still showing both symptoms, so I guess the graphics card is fine

I've now unplugged both hard drives and I'm running Ubuntu off a flash drive. If this crashes I guess I'm buying another motherboard; if not I'll boot back into Windows, back stuff up and try some SSD stress tests.

Thanks again!

 

[randomnine]

Motherboard recommendation?

Replacing the graphics card doesn't help, and swapping the SSD out for another drive doesn't help. So I guess it's the motherboard!

The Asus M4A87TD Evo isn't for sale any more and I don't know what to look for, really. Will the Asus M5A97 Evo work as a straight replacement?

edit: ordered the M5A97 Evo. Ta!

edit #2: Motherboard fixed it. Transferring Windows to the new mobo was an arse but it's fine now and has been stable for the past week ^_^